JPH0569373B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus and method for dispensing a liquid sample in a controlled and predetermined flow pattern, and more particularly to an apparatus and method for dispensing a liquid sample in a controlled and predetermined flow pattern, and more particularly, for detecting a desired amount in a liquid sample by visual or other sensing means. The present invention relates to an apparatus and a method capable of rapidly and uniformly dispensing a defined amount of a liquid sample onto a reactive surface, making it possible to confirm the presence of a component and/or the amount of that component.

Analytical elements have been known for many years. Chemical analysis of biological fluids such as blood and urine, as well as water and food products such as milk, is often desirable and necessary for the health and well-being of all people. Many different configurations for test elements have been developed in the past to facilitate analysis. Some refer to liquid reagents that, when contacted with a liquid sample containing the analyte, form a colored substance or undergo other detectable changes in response to the presence of the analyte. It is useful for the analysis of liquid samples that require addition of substances to be analyzed, called analytes. Other systems rely on drying systems, such as PH test strips, or other highly absorbent carriers that chemically react or respond upon contact with the liquid containing the analyte. , impregnated with a substance that causes a color or other type of change. Depending on the choice of responsive substance, this change is usually qualitative or at most semi-quantitative. For diagnostic chemical analysis, where testing of biological fluids such as blood, plasma, urine, etc. is utilized, it is desirable that highly quantitative results can be obtained quickly and easily. It is also desirable to accurately control and monitor the amount of liquid sample subjected to testing.
This is particularly important for tests that involve mechanical reading of the test substrate to ensure proper reaction and removal of obstructions to optical or other detection of color changes. Thus, it is necessary to bring a defined amount of sample into contact with the test strip.

Various devices and methods have been developed for transferring liquid in a controlled and predetermined inflow pattern.
Most of these were uncontrolled and undirected capillary flows of liquid over the surface. Uncontrolled flow causes problems with the formation of trapped air pockets and incomplete wetting of certain areas of the surface. Air pockets can result in different test data being collected when testing fluid and/or wet surfaces, so when taking readings from the test device by microscopy or other automated methods. A problem arises. This testing and automated system
Since it is based on the assumption that liquid is present in the test area, the absence of fluid in the test area in question will confuse the readings and produce unreliable results. Air pocket problems are particularly common when dealing with shapes that have sharp corners or generally hydrophobic plastic surfaces.

Columbus U.S. Patent No.
A variety of different liquid transfer devices have been developed in the prior art, including those described in US Pat. It describes the equipment that it has.

Other shapes for liquid sample transfer are those described in Columbus U.S. Pat. Provides an exterior drop receiving surface.

The capillary zone disclosed in JP 56-27642 to Columbus et al. consists of two test chambers containing an interactive material capable of reacting with components of a liquid sample and an overflow chamber to drain excess liquid sample. Not separated into rooms. Moreover, it does not have an overflow adjustment bottleneck to prevent sample backflow between the two chambers.

U.S. Patent No. Buissiere et al.
No. 3,690,836 describes a device comprising a capillary space between two plastic plates with a continuous seal around the periphery, containing an uncompacted water-absorbing material filling the capillary space. At least one opening in the top plastic plate provides entry into the reaction chamber.

However, the capillary area is not separated into two chambers, a test chamber and an overflow chamber, and there is no means to prevent sample backflow between the two chambers.

A liquid transfer device with a capillary flow bypass in the second region is shown in Columbus, US Pat. No. 4,473,457. This device has two passages that serve to introduce the sample through two openings.
Two different sample inflows are possible. The two liquids then head towards and flow into a common area. This structural shape of Columbus allows the implementation of potentiometric measurements. Columbus U.S. Patent No. 1, which showed an apparatus suitable for potentiometric analysis of ions in liquids.
According to No. 4,302,313, a special surface with a bottleneck in the lower part of the member 36 is said to control capillary flow.

Another device was published in Columbus' U.S. patent.
No. 4,271,119, which includes flow diversion openings in a wall member of a first capillary section to provide capillary flow in a second capillary section extending from the wall member. There is.

U.S. Pat. No. 4,323,536 to Columbus discloses a multi-analyte test device that incorporates liquid control means so that liquid is confined to multiple inlet passageways.

SUMMARY OF THE INVENTION The present invention relates to a means for measuring the amount of liquid sample applied onto a reaction surface in a novel configuration of capillary gap devices. Here, the capillary device refers to a device having a gap that can cause capillary action, and is not limited to a tubular body. This device rapidly and uniformly dispenses a predetermined amount of a liquid sample onto a reactive surface for determining the presence or absence of a specific component during a liquid test. The amount of sample applied to the reaction surface is limited to the inherent volume of the sample capillary gap or sample reading chamber. Excess sample is drained into an overflow capillary chamber by a proportioning channel that limits the inflow rate, thereby allowing the device to
Allows the sample reading chamber to accommodate excess sample beyond the minimum required without the need for weighing, blotting, wiping or rinsing.

The main problems with dry reagent films and test strips are solved by the present invention, ie, by applying a uniform distribution of the sample onto the reaction surface and controlling the amount of sample.

The above advantages are achieved by changing the capillary gap thickness,
By varying the total volume accommodated in the sample reading chamber of the device, it is possible to select the correct sample volume for the chemical nature and reactivity of the reactive substance.

Excess fluid in excess of the capacity limit of the capillary overflow chamber may be absorbed by paper or other absorbent media mounted near or directly above the appropriate opening of the overflow chamber of the device.

Other features and advantages of the invention will become apparent from the following detailed description taken in conjunction with the drawings.

The major problems associated with dry reagent films and test strips are solved by the apparatus of the present invention. Applying the sample in a uniformly distributed manner over a limited surface area of the test surface is difficult using prior art materials. In many cases, the sample does not enter the sample chamber under suitable conditions, and either too much or too little sample comes into contact with the sample chamber.

The present invention allows for tight and careful monitoring control of the amount of sample such that a predetermined amount of analytical liquid comes into contact with the test surface. These advantages therefore take into account the properties of the fluid being tested and the properties of the reagent film. The purpose is to allow selection of the appropriate sample amount for a particular test. The device of the invention can be made in a variety of different sizes so that the thickness of the capillary gap can be varied as desired. Therefore, the capillary gap device can be made in different dimensions depending on the total amount of sample that is desired to be accommodated. This will depend on the particular means chosen to read the test results, such as automatic or visual means. The device of the present invention provides a means to deal with the problem of excess sample so that excess liquid does not interfere with obtaining proper readings. Therefore, according to the invention, excess fluid flows through the overflow regulating attrition into the overflow chamber and, if necessary, flows out through the overflow hole or opening. If desired, some type of absorbent material is placed at or near the device to absorb excess liquid.

The present invention is more than just a fluid transfer or deployment device;
From a minimum of about 5-10 microliters to about 100-200
It is noteworthy that it is a volumetric metering device that is made to accommodate sample quantities ranging up to microliters.

Therefore, an important feature of the present invention is to provide a fluid metering device that includes a sample chamber of defined volume in a capillary gap structure.

A further feature of the invention is that the air release
It is an object of the present invention to provide a capillary gap device having a capillary lock in a sample supply port for use and to prevent backflow.

A further feature of the invention is to provide a regulated flow of liquid into the capillary overflow chamber which contains an amount of liquid in excess of the minimum amount necessary to fill the sample chamber. If compatible with the selected reagent film chemistry, the volume of the sample chamber can also be varied to accommodate excess sample.

A further feature of the invention is that, by the action of capillary tubes,
The objective is to completely remove the liquid sample from the sample supply port. Therefore, no cleaning or wiping is required, and no excessive sample residue is found in the aperture. In operation according to the invention, any residual sample left in the sample supply port is drawn into the overflow chamber and the sample supply port is emptied. Excess overflow beyond the capacity of the capillary overflow chamber is disposed of by utilizing a water-absorbing pad as an optional feature of the invention.

A further feature of the invention is that the creation of an air gap in the overflow regulation bottleneck allows
No mutual inflow between the liquid in the sample chamber and the liquid in the overflow chamber occurs. This enhances the endpoint chemical reaction that takes place within the sample chamber, depending on the specific nature of the reactive material.

DETAILED DESCRIPTION OF THE INVENTION More specifically, the device of the invention is characterized by capillary transport of biological fluids, in particular whole blood, which are inspected visually or by an automated system for sample reading. shall be. The apparatus can be used with any liquid in the form of droplets, in which a quantity of liquid is transferred from an external surface or liquid source through an aperture to a reaction surface or test substrate. carried to the means. The device according to the invention is characterized in that it meters the amount of sample flowing into a capillary gap which is provided with a sample chamber of defined volume.

The device of the invention, illustrated by the embodiment shown in FIG. 1, has a generally rectangular capillary device having a major axis and a minor axis and comprising an upper layer 2, a spacer layer 3 and a lower layer 4. The lower layer consists of reagent detection means. The upper layer may be transparent or non-transparent, but will be described here as a transparent plastic material, and has an air vent 5, an overflow port 6, and a sample supply or sample inlet 7 on its surface. Be equipped. However, it will be appreciated that the distal end of the device may be provided with an opening or inlet at the bottom, provided this does not interfere with the operation of the device.

The spacer layer 3 defining the internal capillary gap or chamber typically has a capillary lock 9 which matches the size of the upper layer 2 and the lower layer 4 and corresponds to the space below the air vent 5 in the upper layer 2. A sample chamber 8 is formed. The capillary gap can vary, but is usually
It ranges from 0.007 to 0.08 cm. Also formed in the spacer layer is an overflow regulating conduit 10 connecting the sample chamber 8 and the overflow chamber 11 . This overflow chamber 11 is provided below and connected to the overflow hole 6 of the upper layer 2.

The reagent layer 4 may consist of any conventional type of monolayer or multilayer reagent material or substrate as described in more detail below.

The transparent upper layer 2 may be cut or stamped from a suitable material such as the polystyrene material Trycite. Other plastic materials include polyolefins, polyamides, polyesters, etc., as will be apparent to those skilled in the art. Any suitable material can be used, provided it is inert to the sample and is sufficiently strong and stable.

The spacer layer is formed of a suitable material such as a thermoplastic material that can be used to join the upper layer 2 with the reagent bottom layer 4 upon heating. polyamides,
Suitable dimensionally stable thermoplastic materials are used for this purpose, such as polyethylene, polypropylene, polyvinyl chloride, and copolymers thereof. Separate adhesive components may also be interposed between the layers in sufficient amounts to reliably and permanently bond all of the layers. Such adhesive materials are known in the art, but any suitable material that does not react with the sample can be used.

Although the dimensions of the capillary interstitial apparatus can vary widely,
A particularly useful dimension is a length to width ratio of about 3 to 1. i.e. length 2.5-7.5cm (approximately 1-3 inches)
In contrast, the width is 0.8 to 2.4 cm (1/3 to 1 inch). A particularly useful shape is 1 cm (0.4 inch) wide by 3.7 cm (1.4 inch) long. The thickness of the test device can also be varied, typically 0.05
~0.25cm (approximately 0.02-0.1 inch). Typically, the three layers are (1) a 0.02 cm (0.008 inch) thick plastic, such as a polystyrene cover, and (2) approximately 0.02 cm (0.06 inch) thick, cut to approximately the same size, to contain the fluid. (3) a plastic adhesive spacer layer for e.g. 0.02 cm
(0.008 inch) thick polyethylene terephthalate film substrate with a reactive lower layer of gelatin-based coating material.

In FIG. 2, the air vent 5 shown in FIG.
2 shows an embodiment of the upper layer showing the overflow 6 and the sample supply port 7; The dimensions of these openings can be varied, as can their arrangement. Most conveniently, they are circular apertures, since they can be easily drilled or stamped into the sheet. However, in FIG. 2, the overflow holes are shown as rectangular, a shape that can be cut out with a suitable cutting die. The air vent 5 may be relatively small, for example about 0.08 cm (0.03 inch) in diameter.
, located on the central long axis of the upper layer 2 and at a small distance from the end, e.g. 0.06 cm.
(0.025 inch) and approximately 0.1 cm (0.04 inch) from the end to the center of the circle. Therefore, if the width of the upper layer cover is, for example, 1 cm (0.04 inch), the center line of the air vent 5 will be 0.5 cm (0.2 inch) from the edge of the longer side. The rectangular overflow port 6 is located a short distance (for example, 0.1 cm or 0.04 inch) from the end opposite to the end where the air vent 5 is provided. The dimensions of the overflow port can vary, for example 0.3 x 0.5
cm (0.1 x 0.2 inches) has been found to be suitable. The overflow port, like the air vent, is usually centered on the main axis of the device.

The sample supply port 7 may be circular and usually has a larger diameter than the air vent port 5. For example, the diameter of the sample supply port is usually 3 to 4 times the diameter of the air vent 5.
It's double. Therefore, based on the dimensions described above, the preferred dimensions for the sample supply port are 0.3 cm (0.1 inch) in diameter. The sample supply port 7 may be located at the center of this device, but does not necessarily need to be located at the center. It is important that the sample supply opening is arranged in such a way that it is connected to the sample chamber 8 and adjacent to the overflow regulating conduit 10 .

FIG. 3 shows a plan view of the spacer chamber layer 3 with the sample chamber 8 and the overflow chamber 11 communicating with each other by an overflow regulating attrition 10 and also shows the capillary lock 9. FIG. The several different areas in the spacer layer 3 are all located symmetrically with respect to the main axis of the device. The capillary lock 9 and the overflow regulating attrition have a relatively small area compared to the sample chamber 8 and the overflow chamber 11. For example, the width of this lock and bottleneck is 0.08 cm (0.03 inch), while the width of the sample chamber and overflow chamber is 0.08 cm (0.03 inch).
0.8 cm (0.03 inch), or approximately a 10:1 ratio, although the exact and relative dimensions may vary. Generally, a ratio of 2:1 to 50:1 is used. The spacer chamber may be formed of a thermoplastic resin that acts as an adhesive to fuse the three layers together. Alternatively, conventional adhesives may be used to bond the layers together.
As a further variant, ultrasonic or laser means may be used to make the proper bond. As a further variant, mechanical fasteners may also be used to securely bond the layers together.

FIG. 4 is an end cross-sectional view of the device showing the upper layer, spacer layer and lower layer. The lower layer 4 is a layer containing a reagent and may be a layer of fibers impregnated with a reagent or a layer coated with gelatin. Any of a variety of reagent layers or substrates are suitable for use in the present invention, including powders. Many conventional reagent systems are available, and the specific selection of reagents
Determined based on tests conducted.

FIG. 5 is a perspective view of another embodiment of the capillary gap device 1 of the invention, consisting of three layers: a transparent upper or cover layer 2, a spacer layer 3 and a reagent film layer 4. In this embodiment, the reagent film layer 4 comprises an extension 20 having a water-absorbing material thereon which absorbs liquid overflowing from the overflow chamber 11. In this variant there is no overflow port in the upper layer. Instead, the overflow flows directly from the end of the device into the extension 20 of the reagent layer 4.
Furthermore, in this embodiment, the wall surface of the chamber has a curved contour avoiding sharp corners.

Figure 6 shows air vent port 5 and overflow port 6.
and a sample supply port 7. 3 is a plan view of another further embodiment of the invention; FIG. The sample chamber 8 and the overflow chamber 11 are designed without sharp corners so that they can be seen through the transparent upper layer 2.

FIG. 7 shows another embodiment of the invention and is a plan view of a capillary gap device. Upper layer 2 and reagent layer 4
(See Figure 8) is an adhesive (not shown in Figure 7).
It is joined by In this embodiment, there is no spacer layer. The upper layer has, within itself, an air vent 5, a capillary lock 9, a sample chamber 8, a sample supply opening 7, a regulating channel 10, an overflow chamber 1.
1 and an overflow port 20 are formed.
In addition, this upper layer serves to concentrate the sample droplets, to guide them into the sample supply opening 7 and to remove the sample from the applicator, for example a finger. Excited ring 21
is formed around this sample supply port.

FIG. 8 shows a cross-sectional view of the embodiment of FIG.
In this embodiment, the upper layer is shaped to form upwardly extending chambers 8 and 11 therein, while the reagent layer is flat-ended. An adhesive material 22 is used between the upper layer 2 and the reagent layer 4, and this 2
The layers are joined together. A ring 21 is shown around the sample supply port 7. It will be appreciated that the reagent material may also be provided with an adhesive layer around its periphery to enable bonding or heat sealing with the upper layer without the use of a separate adhesive member.

A further embodiment of the invention is shown in perspective view in FIG. 9 and has a transparent cover layer 2 in which a sample supply port 7 and an overflow port 6 are formed. The spacer layer 3, in which a plurality of chambers are formed, can be made of any suitable material and has a capillary lock 9, a sample chamber 8, an overflow metering regulator 10 and an overflow chamber 11 formed therein. By staggering the ends of these layers, the end of the capillary lock 9 protrudes from the end of the cover layer 2 and serves as an air vent.

Reagent layer 4 may be any suitable reagent material.

A further embodiment of the invention is illustrated in Figure 10, which shows an enlarged view of the capillary gap device of the invention. The device consists of a transparent upper layer 2 having an air vent 5, an overflow hole 6 and a sample introduction port 7 therein. An overflow chamber 11, a sample supply chamber 8 and a capillary lock area 9 are formed on the underside of this upper layer. This upper layer may include sealing ridges or slightly thickened portions 26 along the edges of the chambers and defiles. The lower layer is provided with grooves 24 for holding reagents. The lower layer is made of transparent plastic or other material to allow viewing through its transparent surface. The longitudinal bottleneck for the reagent is slightly thinner than the thickness of the reagent film. The lower layer has a longitudinally raised end surface that enables welding or gluing of the lower layer and the upper layer, and is formed of heat-sealable plastic or has an adhesive thereon. do. Preferably, the upper layer is formed from a thermoplastic material that allows the upper and lower surfaces to fuse together when heated or ultrasonic welded.

FIG. 10A shows the top surface of the upper layer 2 shown in FIG. In this embodiment, the sample supply port 7
serves to concentrate and introduce the sample droplets into the device. A raised ring portion 21 is provided.

FIG. 11 is a schematic side view of the three elements used to form the intercapillary device of the present invention. The upper layer 2 and the lower layer or reagent layer 4 are as described above. The spacer layer 3 is made of a thermodeformable plastic material and forms the deficiencies and chambers by stamping or shaping. The upper and lower surfaces of layer 3 are provided with depressions, cones or protrusions thereon, allowing good welding and bonding to each other when integrating these layers.

FIG. 12 shows that a glucose film in a capillary gap format is placed in the commonly used open format, i.e., blood is deposited on the surface of the glucose film confined to a small area by holes in the plastic covering layer. Concentration response test (dose response test)
The results of the experiment are shown below. The reactivity of the film in capillary gap format is significantly higher than that in open format. In open format, one reason for this is evaporative cooling of the exposed sample, which reduces the sample temperature by about 2.5°C. As shown in FIG. 13, analytical accuracy is improved by a factor of two in the capillary gap format, as evidenced by the lower coefficient of variation (CV) at each glucose concentration.

For example, according to the invention shown in FIG. 1, the capillary gap device 1 comprises a multilayer reagent film as the lower layer 4, the film base of which is the lower layer, a double-sided adhesive plastic layer as the spacer layer 3, and a double-sided adhesive plastic layer as the spacer layer 3. It may also be constructed with a top plastic covering layer 2. Sample chamber 8, overflow chamber 11, overflow adjustment bottleneck 10, and capillary lock bottleneck 10
The shape of is determined by providing holes in the adhesive layer, and the entrances to these chambers are provided by openings 5, 6 and 7 in the plastic cover layer.

Also, a pattern of adhesive according to the desired chamber and bottleneck shapes can be printed or screen printed onto the inner surface of the covering layer to whatever thickness is required.

It should be noted that the rectangular chamber shape shown in FIG. 1 can be formed with conventional tools for die-cutting adhesive films. A more preferred embodiment is one with a rounded profile as shown in FIG. The rounded outline
Usually obtained by molding techniques.

A further manufacturing method consists in forming the capillary channels and chambers directly in the plastic coating layer. This embodiment of the invention allows for the creation of shapes with complex, smooth, rounded contours by using an appropriately shaped mold or die and applying reduced or increased pressure along with heating. Adhesive means are then used to adhere the formed plastic coating to the reagent film without significantly increasing the thickness of the device. It should be noted that arrangements for other devices using similar general principles can be applied to this capillary gap device.

In operation, a blood or fluid sample containing a desired analyte, such as glucose, is applied to a sample supply port, for example. Typically, this device has a minimum of approximately 20
Capable of handling microliter samples. Excess sample remains in the sample inlet for a short time and is sucked into the overflow chamber by capillary action. This usually occurs within about 20 seconds, by which time the sample supply port is completely free of sample. The initial filling of the sample chamber takes no more than a few seconds, typically about 2 seconds. Also, this time is limited only by the rate at which the sample is fed into the sample feed port.

In a further embodiment of the invention, shown in FIG. 11, the capillary gap device is formed by a three-layer structure. The upper layer 2 is a transparent plastic such as polystyrene. The spacer layer 3 is an internal structure made of thermoplastic material and having a bottleneck and a chamber (not shown). Also formed on the upper and lower surfaces of the layer 3 are depressions, protrusions and/or cone-shaped protrusions for guiding welding energy, which pierce the gelatin layer of the lower layer 4 of the reagent film. Typically, the lower layer 4 is formed of a reagent film, such as a gelatin coated layer, with the gelatin side facing the top side. Spacer layer 3 made of a thermoplastic material that is fusible under the conditions used for ultrasonic welding
When composited and fused together by means such as ultrasonic welding, they fuse with the upper layer 2 and the lower layer 4, providing a uniform and secure seal between each member. In this method, a large sheet of material is first formed and then cut to the desired dimensions by ultrasonic or laser welding. Additionally, this device may simultaneously perform bonding and cutting using ultrasonic or laser means.

As mentioned above, the main purpose of the device of the present invention is to enable the metering of a defined amount of sample onto a reactive surface or channel without the need for metering, washing or wiping the sample. In the device shown here, excess sample is drawn into the overflow chamber at a rate determined by the dimensions of the conditioning bottleneck. Furthermore, in the apparatus of the present invention, the sample connection between the sample chamber and the overflow chamber is broken once the overflow chamber has sucked in excess liquid sample. Capillary locks work to prevent backflow. The inner surfaces of the upper and lower layers of the device should be made of materials with equal wetting angles. One way to do this is to apply a surfactant to one or all surfaces.

Any reagent containing at least one substance that is interactive or reactive with respect to the presence of an analyte-positive liquid present in the sample to be tested may be used for the purposes of the present invention. Good too. In many cases, the interactive substance is reactive with the analyte or with a precursor or reaction product of the analyte, and the effect of the reactive substance causes a change in the device. The reagent layer is therefore permeable to at least one component present in the sample;
It is preferred to have substantially uniform permeability to the substance being tested in the sample. As used herein, the term "permeability" refers to the ability of a substance held in a liquid sample to effectively penetrate a substance or layer. Uniform permeability of a layer means that when a homogeneous liquid is applied uniformly to the surface of the layer, the same measurement of such sample concentration in the layer can be made in different areas of the surface of this layer. . Permeability is such that each measurement yields substantially identical results within a range of about 10%. Due to the uniform permeability, undesirable concentration gradients in the reagent layer can be prevented. Such reagent layers are known in the art and any suitable ones can be used for the purposes of the present invention.

One or more surfactants are used to coat the interior of the chamber in this device to enable and facilitate transfer of the sample into the sample chamber and an overflow chamber for excess liquid. A wide variety of ionic and nonionic surfactants are used for this purpose. For example, well-known ionic surfactants such as alkali metal and alkyl sulfates are used, where the alkyl group has more than 8 carbon atoms, such as sodium dodecyl sulfate. Examples of nonionic surfactants include "Determinants and Emulsifiers" by Matsucation;
In 1974, North American Edition by the Allard Publishing Corporation (McCutcheon's “Detergents and
Emulsifiers”1974, North American Edition
A number of examples are used, such as those described by the Allured Publishing Corporation.

The analytical element of the present invention is applicable not only to the field of clinical chemistry but also to the implementation of a wide variety of chemical analyzes in the field of chemical research and chemical process control laboratories. Theoretically, the invention can also be used in low gravity conditions, including conditions found in outer space. Because this work involves a large number of repeated tests, and test results are often required within a very short time after sample collection, the present invention makes it possible to Very suitable for testing use. In the field of blood testing, for example, multilayer elements are applied in performing quantitative analyzes of the many routinely measured blood components. Therefore, for example, this element can easily be used for the analysis of blood components such as urea nitrogen, chlorine, glucose and uric acid, as well as many other components with appropriate selection of test reagents or other interacting substances. Can be adapted. In blood analysis using the analytical element of the present invention, blood cells and serum are separated by means such as centrifugation, and the serum is applied to the element. However, especially if reflectance spectrophotometry is used for the quantification or other analysis of the reaction products formed in the device, whole blood is applied directly to the device and the blood cells are superimposed on the device. Such separation is not necessary since it is taken by action. The presence of blood cells in the element does not interfere with the spectrophotometric analysis if the analysis is carried out by reflection.

The reagent layer of the device according to the invention is permeable or porous to the samples obtained from the metering or spreading layer or to their reaction products. The multilayer reagent layer may have a metering layer or a spreading layer. As used herein, the term "permeability" includes permeability resulting from porosity, swelling ability, or other properties. The reagent layer may have an interactive substance distribution, for example a dissolved or dispersed matrix. The choice of matrix material is, of course, variable and will depend on the intended use of the device.
Desirable matrix materials include hydrophilic materials such as hydrophilic colloids, preferably in the form of water-swellable gels. Useful hydrophilic materials include gelatin; gelatin derivatives; hydrophilic cellulose derivatives; naturally occurring substances such as polysaccharides such as dextran, gum arabic, agarose, etc., and water-soluble polyvinyl compounds such as polyvinyl alcohol and polyvinylpyrrolidone; Both synthetic materials such as acrylamide polymers. Organophilic materials such as cellulose esters and the like are also useful, and in any case the matrix material is selected depending on the intended use of the particular device.

To increase the permeability of the reagent layer, if it is not porous, it is often useful to use a matrix material that is swellable in the solvent, dispersion medium or liquid being analyzed. The choice of reagent layer matrix may depend in part on its optical or other properties, which in any case may affect radiation detection. The reagent layer must not interfere with the detection of the intended result. It is also necessary to select suitable materials for the formation of adjacent layers, by means such as coating, during the manufacture of the device. For example, if it is desirable to form separate layers and the intended analysis is the analysis of an aqueous sample, a substantially water-soluble matrix is selected for the reagent layer and an adjacent layer, such as the spreading layer. It is appropriate to select substantially organic soluble or organic dispersible components. In such a method, solvent interactions are minimized and a contoured layer configuration is formed. In many cases, the permeability of the reagent layer is lower than that of the developer layer to facilitate achieving apparent concentration uniformity in the developer layer, as described herein. It is desirable to do so. Relative permeability is determined by known techniques.

In various embodiments of the device of the invention, the interactive substance in the reagent layer reacts with the analyte to which the device responds. In other embodiments, the interactive agent may be reacted with the precursor or product of the analyte, if appropriate given the chosen analytical mechanism. The term "interactive" is used herein to mean reactivity by addition, protonation, decomposition, etc.; actions such as in the formation of enzyme-substrate complexes; and actions such as those occurring as a result of enzymatic action. and any other chemical agent capable of producing or promoting a radiologically detectable change in the element, e.g. in the reagent layer, i.e. a change detectable by appropriate measurement of light or other electromagnetic radiation. or refers to the form or composition of physical interaction.

Distribution of the interactive substance is achieved by dissolving or dispersing it in the matrix material. Although uniform distribution is often preferred, it is not necessary if the interacting agent is, for example, an enzyme. Reagents or other interactive substances that are soluble in the liquid to be analyzed are advantageously immobilized in the reagent layer, especially if the reagent layer is porous.

The specific interactive substances distributed in the reagent layer will depend on the assay selected.

Ferricyanide is used in the case of glucose analysis. Glucose reacts with ferricyanide, and this reaction causes a decrease in the yellow character of ferricyanide. In the test for uric acid, as in the case of serum, a mixture of copper sulfate and neocuproine is distributed in the reagent layer matrix. Uric acid reduces cupric compounds to cuprous compounds that can form complex compounds with neocuproine, forming a colored substance whose concentration is proportional to the uric acid concentration in the analysis sample. For many assays, enzymes, such as oxidase substances such as glucose oxidase, are substrates for such enzymes.
Preferably, it is included as an interactive substance in a reagent layer of an element intended for analysis of an analyte. For example, oxidative enzymes include peroxidases or peroxidizing substances and chromogens or peroxidases (or other substances that have a peroxidizing effect) and the presence of hydrogen peroxide formed upon interaction of peroxide with its substrate. It can be included in the reagent layer with a composition that provides a dye or other detectable species upon subsequent oxidation. Upon proper interaction,
An interactive substance that directly produces a detectable change in the device is also called an indicator. A plurality of substances that include at least one interactive substance and that work together to cause a detectable change in the device are collectively referred to as an indicator composition.

Chromogens or compositions that include an oxidizable moiety and can provide a detectable species include certain dyes that provide a substance or composition. On the one hand, pigments are
When oxidized, it is given by a compound that combines with itself or with its reduced form to produce a pigment. Such self-binding compounds include orthoaminophenols, alkoxynaphthols, 4-amino-5-pyrazolones, cresols, pyrogallol, guaiacol, orcinol, catecholphloroglucinol, p,p-dihydroxydiphenyl, There are various hydroxides such as gallic acid, pyrocatecholic acid, salicylic acid, etc. Compounds of this type are well known and are described in The Theory of the Photographic Process by Mees and James.
Photographic Process, Mees and James
Ed.), (1966), especially in Chapter 17. In another aspect, the detectable species is obtained by oxidation of a leuco dye and is obtained in the form of its corresponding dye. Representative leuco dyes include compounds such as leucomalachite green and leucophenolphthalein. Furthermore, in other aspects,
The detectable species is obtained from the dye and the coupler forming a composition including an oxidizing compound capable of undergoing oxidative condensation with the coupler, such as one containing a phenol group or an activated methylene group. Representative such oxidizing compounds include compounds such as benzidine and its homologs, p-phenylenediamines, p-aminophenols, 4-aminoantipyrine, and the like. Such couplers, including a large number of self-binding compounds, have been extensively described in the literature.

Certain substances or compositions also include reducible moieties that can yield radiologically detectable compounds. This compound is formed or destroyed by a reduction process. An example of the former chemical reaction is during direct radiometric measurements of reduced NAD, such as that formed by the reaction of glucose with glucose dehydrogenase and NAD (nicotinamide adenine dinucleotide), typically seen at a wavelength of 340 nanometers. and also in the further reaction of reduced NAD with diafluorase and any one of various tetrazolium compounds and subsequent radiometric detection of the resulting formazan. A specific example of such a tetrazolium is iodonitrotetrazolium chloride (INT), which yields a red formazan upon reduction. 2,6-dichlorophenolindophenol is an example of a compound whose color is destroyed upon reduction.

This reagent element layer may be transparent, if desired, so that it can be read from the bottom surface. This layer is
It can have various binding compositions, for example gelatin, cellulose butyrate, polyvinyl alcohol, agarose, etc., the degree of hydrophilicity depending on the material chosen. Gelatin is generally suitable to act as a layer during blood testing, since it acts as a wetting agent that creates a unique flow of sample into the capillary area.

Additional layers may be provided to provide various chemical reactions or functions, or functions that cooperate with themselves or with other reagent layers. In this way, multiple layers are utilized. Permeability, registration or mordant functions are provided by additional layers. There are many examples of composite layers in the prior art, such as those found in US Pat. Nos. 4,042,335 and 4,050,898.

As used herein, "reagent" and "reagent layer"
The term refers to a substance that can interact with a precursor of an analyte, a degradation product or an intermediate of the analyte. For example, one of the reagents may be a radiologically detectable species that is transferred by the analyte from a radiopaque region or layer in the device to a radiologically transparent region or layer, such as a registration layer. It may be hot.

Thus, the interaction of the reagents in the reagent composition with the analyte may result in a chemical reaction, the action of an enzyme, such as in the formation of an enzyme-substrate complex, or, ultimately, a radiologically detectable signal in the device. means other forms of chemical or physical interaction, including physical displacement, which can give rise to

According to the present invention, by using a white or light colored reagent film and an opaque or black cover sheet, it is confirmed that the sample chamber is filled, and then the appearance of the sample is observed through the air vent. It becomes possible to do so. Excellent temperature control properties are achieved with the present invention for non-capillary as well as many other capillary devices as substantially the liquid sample remains free from contact with the atmosphere.

This means that the present invention almost completely excludes the effects of evaporative cooling. Once the device is filled with sample, it can be oriented in any manner. No air-filled space remains in the sample chamber and no sample escapes. To ensure uniform distribution of the sample, the initial filling should be performed on a reasonably horizontal surface. The analyte sensitive surfaces contained in the device are
Except for the opening in the top coating layer, it is surrounded and protected from damage and decomposition caused by the outside environment.

Further modifications and variations of the invention will be apparent from the foregoing and are included within the scope of the claims.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of one embodiment of the capillary gap device of the present invention. FIG. 2 is a plan view of the upper layer with an aperture or inlet formed therein of one embodiment of the capillary gap device of the present invention. FIG. 3 is a plan view of a cavity-shaped spacer layer of one embodiment of the capillary gap device of the present invention. Figure 4 shows line 4 in Figure 1.
4 is an end view of the capillary gap device along -4; FIG. Fifth
The figure is a perspective view of another embodiment of the invention. FIG. 6 is a plan view showing another configuration of the present invention.
FIG. 7 is a plan view of another embodiment of the invention. FIG. 8 shows the line 8-- of the embodiment shown in FIG.
FIG. 8 is an end view taken along line 8; FIG. 9 is a perspective view of another embodiment of the invention. FIG. 10 is an exploded view of another configuration of the present invention. Figure 10A shows the 10th
FIG. 3 is a perspective view of the upper layer shown in the figure; Figure 11 shows
FIG. 7 is a schematic side view showing a special shape of a spacer layer according to another embodiment of the present invention. FIG. 12 is a graph showing reactivity per second and shows the effect of format design on the concentration-response film curve of a glucose sensitive film. FIG. 13 shows a comparison of the test accuracy of open format and capillary gap format test devices.

Claims (1)

[Scope of Claims] 1. An upper layer and a lower layer are arranged opposite to each other so as to define a capillary area between the layers for transporting a liquid sample, and the layers are separated within a distance that can maintain a capillary flow of the liquid sample. and wherein the capillary zone comprises a sample testing chamber holding an interactive material capable of reacting with a component in the liquid sample to produce a detectable response and an overflow chamber discharging excess liquid sample. In a capillary device for use in a capillary chamber, the liquid sample is allowed to overflow from the sample test chamber to the overflow chamber, and
an overflow that acts as a capillary lock to break the communication between the liquid sample in the sample test chamber and the liquid sample in the overflow chamber and to prevent backflow of the liquid sample from the overflow chamber to the sample test chamber; a conditioning attrition is disposed between said sample testing chamber and said overflow chamber; and means for defining a sample inlet for introducing a liquid sample into said capillary zone are in communication with said sample testing chamber. A capillary device for measuring an inflow amount for controlling an inflow amount of a liquid sample, characterized in that the capillary device is arranged so as to be in an adjacent relationship with the overflow adjustment attrition channel. 2. The device according to claim 1, wherein the distance between the upper layer and the lower layer arranged opposite to each other is 0.007 to 0.08 cm. 3. Claim 1, wherein the upper layer is transparent
Apparatus described in section. 4. The device of claim 1, wherein the interactive material is a responsive layer impregnated with a reagent. 5. The device of claim 1 further comprising an adhesive layer interposed between the surface layers for sealingly bonding the surface layers to each other. 6. The device of claim 1, wherein said bottleneck and said chamber are formed in said surface layer. 7. The device of claim 1, wherein the chamber is rectangular. 8. The device of claim 1, wherein the chamber is shaped with a curved profile. 9. The device of claim 1, further comprising a water-absorbing layer between said layers. 10. The device of claim 1, wherein the interactive material is a multiple reagent layer. 11. The device of claim 1, wherein the surface of the capillary zone is coated with a surfactant. 12. The device according to claim 1, wherein the sample supply port is arranged on a side surface of the device. 13. The device of claim 1, wherein the sample supply port is located at an end of the device. 14. A patent in which the sample test chamber and the overflow chamber have a relatively large diameter, the bottleneck connecting the two chambers has a relatively small diameter, and the bottleneck is adjacent to a sample supply port. An apparatus according to claim 1. 15. The sample supply port comprises a sample inlet located at one end of the device, the sample inlet being a relatively narrow passageway connected to a relatively wide sample testing chamber, and the overflow chamber being an overflow metering attrition. 2. A device as claimed in claim 1, wherein the device is thus connected to said relatively narrow passageway. 16. Claim 1 comprising means for removing excess liquid sample from said overflow chamber.
Apparatus described in section. 17 said upper layer having means defining an air vent for venting air from said sample testing chamber, said means for removing excess liquid sample being connected to said overflow chamber for removing excess liquid sample; 17. The apparatus of claim 16, further comprising means for defining an overflow port. 18. The device of claim 1, wherein the device is rectangular in shape with a major axis and a minor axis. 19. Device according to claim 1, whose dimensions are 3.7 cm long and 1 cm wide. 20. The apparatus of claim 1, wherein the sample introduction port comprises a raised annular ring on the upper surface of the means defining the sample supply port. 21. The device according to claim 20, whose thickness is between 0.05 and 0.25 cm. 22 an upper layer, a lower reagent-interactive layer, and a spacer layer located between these layers defining a capillary zone for the transfer of a liquid sample, said capillary zone for the transfer of a liquid sample introduced into said zone. a sample test chamber having dimensions within a distance capable of sustaining capillary flow, and said capillary zone containing an interactive material capable of reacting with components of the liquid sample to produce a detectable response; In a capillary device for metering inflow which is divided into an overflow chamber and an overflow chamber, the capillary device is arranged between the sample test chamber and the overflow chamber to allow overflow of the liquid sample from the sample test chamber to the overflow chamber. an overflow control bottleneck acting as a capillary lock to sever the liquid sample communication between the sample testing chamber and the overflow chamber to prevent backflow of the liquid sample from the overflow chamber to the sample testing chamber; means for defining a sample inlet for introducing a liquid sample into the capillary zone, the means being arranged in communication with the sample testing chamber and in adjacent relationship with the overflow regulation attrition; A capillary device for measuring an inflow amount for controlling an inflow amount of a liquid sample, characterized in that: 23. Device according to claim 22, whose dimensions are 0.007 to 0.08 cm. 24. The apparatus of claim 22, wherein said sample test chamber includes means for defining an air vent. 25. The apparatus of claim 22, further comprising an adhesive layer formed on the underside of the upper layer and positioned in sealing relationship with the spacer layer. 26 Claim 2, wherein both chambers are rectangular
The device according to item 2. 27. The device of claim 22, wherein both chambers are shaped with a curved profile. 28. The device according to claim 22, further comprising a water-absorbing layer between the upper layer and the lower layer. 29. The device of claim 22, wherein the interactive layer is a multiple reagent layer. 30. The device of claim 22, whose dimensions are 3.7 cm long and 1 cm wide. 31. The apparatus of claim 22, wherein the sample introduction port comprises a raised annular ring around its periphery on the surface defining the inlet. 32. A device according to claim 22, whose thickness is between 0.05 and 0.3 cm. 33. Claim 22, wherein the surface of the upper layer facing the capillary area is coated with a surfactant.
Apparatus described in section. 34 Claim 22 in which the upper layer is transparent
Apparatus described in section. 35. The device of claim 22, wherein the spacer layer is a thermoplastic layer that interconnects the upper layer and the interactive layer. 36 supplying a liquid sample to a liquid sample supply port of a test device to a reaction chamber containing an interactive material capable of reacting with a component in the supplied liquid sample to produce a detectable response; A liquid sample in excess of the volume of the reaction chamber is guided to an overflow chamber to prevent the liquid sample from flowing back from the overflow chamber to the reaction chamber. a second capillary channel provided therein, wherein both capillary channels are sized to maintain a capillary flow of the liquid sample, and the sample supply port is in communication with the document chamber. A method for introducing a liquid sample into a capillary test device, characterized in that the liquid sample is placed in a capillary tube and adjacent to the second capillary canal.